Eliminate circular dependency in validation rules

src/utilities/isValidLiteralValue.js

@@ -15,7 +15,7 @@ import { visit, visitWithTypeInfo } from '../language/visitor';
 import type { GraphQLInputType } from '../type/definition';
 import { GraphQLSchema } from '../type/schema';
 import { ValuesOfCorrectType } from '../validation/rules/ValuesOfCorrectType';
-import { ValidationContext } from '../validation/validate';
+import ValidationContext from '../validation/ValidationContext';
 
 /**
  * Utility which determines if a value literal node is valid for an input type.

src/validation/ValidationContext.js

@@ -0,0 +1,221 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ */
+
+import type { ObjMap } from '../jsutils/ObjMap';
+import { GraphQLError } from '../error';
+import { visit, visitWithTypeInfo } from '../language/visitor';
+import { Kind } from '../language/kinds';
+import type {
+  DocumentNode,
+  OperationDefinitionNode,
+  VariableNode,
+  SelectionSetNode,
+  FragmentSpreadNode,
+  FragmentDefinitionNode,
+} from '../language/ast';
+import { GraphQLSchema } from '../type/schema';
+import type {
+  GraphQLInputType,
+  GraphQLOutputType,
+  GraphQLCompositeType,
+  GraphQLField,
+  GraphQLArgument,
+} from '../type/definition';
+import type { GraphQLDirective } from '../type/directives';
+import { TypeInfo } from '../utilities/TypeInfo';
+
+type NodeWithSelectionSet = OperationDefinitionNode | FragmentDefinitionNode;
+type VariableUsage = { node: VariableNode, type: ?GraphQLInputType };
+
+/**
+ * An instance of this class is passed as the "this" context to all validators,
+ * allowing access to commonly useful contextual information from within a
+ * validation rule.
+ */
+export default class ValidationContext {
+  _schema: GraphQLSchema;
+  _ast: DocumentNode;
+  _typeInfo: TypeInfo;
+  _errors: Array<GraphQLError>;
+  _fragments: ObjMap<FragmentDefinitionNode>;
+  _fragmentSpreads: Map<SelectionSetNode, $ReadOnlyArray<FragmentSpreadNode>>;
+  _recursivelyReferencedFragments: Map<
+    OperationDefinitionNode,
+    $ReadOnlyArray<FragmentDefinitionNode>,
+  >;
+  _variableUsages: Map<NodeWithSelectionSet, $ReadOnlyArray<VariableUsage>>;
+  _recursiveVariableUsages: Map<
+    OperationDefinitionNode,
+    $ReadOnlyArray<VariableUsage>,
+  >;
+
+  constructor(
+    schema: GraphQLSchema,
+    ast: DocumentNode,
+    typeInfo: TypeInfo,
+  ): void {
+    this._schema = schema;
+    this._ast = ast;
+    this._typeInfo = typeInfo;
+    this._errors = [];
+    this._fragmentSpreads = new Map();
+    this._recursivelyReferencedFragments = new Map();
+    this._variableUsages = new Map();
+    this._recursiveVariableUsages = new Map();
+  }
+
+  reportError(error: GraphQLError): void {
+    this._errors.push(error);
+  }
+
+  getErrors(): $ReadOnlyArray<GraphQLError> {
+    return this._errors;
+  }
+
+  getSchema(): GraphQLSchema {
+    return this._schema;
+  }
+
+  getDocument(): DocumentNode {
+    return this._ast;
+  }
+
+  getFragment(name: string): ?FragmentDefinitionNode {
+    let fragments = this._fragments;
+    if (!fragments) {
+      this._fragments = fragments = this.getDocument().definitions.reduce(
+        (frags, statement) => {
+          if (statement.kind === Kind.FRAGMENT_DEFINITION) {
+            frags[statement.name.value] = statement;
+          }
+          return frags;
+        },
+        Object.create(null),
+      );
+    }
+    return fragments[name];
+  }
+
+  getFragmentSpreads(
+    node: SelectionSetNode,
+  ): $ReadOnlyArray<FragmentSpreadNode> {
+    let spreads = this._fragmentSpreads.get(node);
+    if (!spreads) {
+      spreads = [];
+      const setsToVisit: Array<SelectionSetNode> = [node];
+      while (setsToVisit.length !== 0) {
+        const set = setsToVisit.pop();
+        for (let i = 0; i < set.selections.length; i++) {
+          const selection = set.selections[i];
+          if (selection.kind === Kind.FRAGMENT_SPREAD) {
+            spreads.push(selection);
+          } else if (selection.selectionSet) {
+            setsToVisit.push(selection.selectionSet);
+          }
+        }
+      }
+      this._fragmentSpreads.set(node, spreads);
+    }
+    return spreads;
+  }
+
+  getRecursivelyReferencedFragments(
+    operation: OperationDefinitionNode,
+  ): $ReadOnlyArray<FragmentDefinitionNode> {
+    let fragments = this._recursivelyReferencedFragments.get(operation);
+    if (!fragments) {
+      fragments = [];
+      const collectedNames = Object.create(null);
+      const nodesToVisit: Array<SelectionSetNode> = [operation.selectionSet];
+      while (nodesToVisit.length !== 0) {
+        const node = nodesToVisit.pop();
+        const spreads = this.getFragmentSpreads(node);
+        for (let i = 0; i < spreads.length; i++) {
+          const fragName = spreads[i].name.value;
+          if (collectedNames[fragName] !== true) {
+            collectedNames[fragName] = true;
+            const fragment = this.getFragment(fragName);
+            if (fragment) {
+              fragments.push(fragment);
+              nodesToVisit.push(fragment.selectionSet);
+            }
+          }
+        }
+      }
+      this._recursivelyReferencedFragments.set(operation, fragments);
+    }
+    return fragments;
+  }
+
+  getVariableUsages(node: NodeWithSelectionSet): $ReadOnlyArray<VariableUsage> {
+    let usages = this._variableUsages.get(node);
+    if (!usages) {
+      const newUsages = [];
+      const typeInfo = new TypeInfo(this._schema);
+      visit(
+        node,
+        visitWithTypeInfo(typeInfo, {
+          VariableDefinition: () => false,
+          Variable(variable) {
+            newUsages.push({ node: variable, type: typeInfo.getInputType() });
+          },
+        }),
+      );
+      usages = newUsages;
+      this._variableUsages.set(node, usages);
+    }
+    return usages;
+  }
+
+  getRecursiveVariableUsages(
+    operation: OperationDefinitionNode,
+  ): $ReadOnlyArray<VariableUsage> {
+    let usages = this._recursiveVariableUsages.get(operation);
+    if (!usages) {
+      usages = this.getVariableUsages(operation);
+      const fragments = this.getRecursivelyReferencedFragments(operation);
+      for (let i = 0; i < fragments.length; i++) {
+        Array.prototype.push.apply(
+          usages,
+          this.getVariableUsages(fragments[i]),
+        );
+      }
+      this._recursiveVariableUsages.set(operation, usages);
+    }
+    return usages;
+  }
+
+  getType(): ?GraphQLOutputType {
+    return this._typeInfo.getType();
+  }
+
+  getParentType(): ?GraphQLCompositeType {
+    return this._typeInfo.getParentType();
+  }
+
+  getInputType(): ?GraphQLInputType {
+    return this._typeInfo.getInputType();
+  }
+
+  getParentInputType(): ?GraphQLInputType {
+    return this._typeInfo.getParentInputType();
+  }
+
+  getFieldDef(): ?GraphQLField<*, *> {
+    return this._typeInfo.getFieldDef();
+  }
+
+  getDirective(): ?GraphQLDirective {
+    return this._typeInfo.getDirective();
+  }
+
+  getArgument(): ?GraphQLArgument {
+    return this._typeInfo.getArgument();
+  }
+}

src/validation/index.js

@@ -7,7 +7,11 @@
  * @flow strict
  */
 
-export { validate, ValidationContext } from './validate';
+export { validate } from './validate';
+
+// https://github.com/tc39/proposal-export-default-from
+import ValidationContext from './ValidationContext';
+export { ValidationContext };
 
 export { specifiedRules } from './specifiedRules';
 

src/validation/rules/ExecutableDefinitions.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import { Kind } from '../../language/kinds';
 import type { ASTVisitor } from '../../language/visitor';

src/validation/rules/FieldsOnCorrectType.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import suggestionList from '../../jsutils/suggestionList';
 import quotedOrList from '../../jsutils/quotedOrList';

src/validation/rules/FragmentsOnCompositeTypes.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import { print } from '../../language/printer';
 import type { ASTVisitor } from '../../language/visitor';

src/validation/rules/KnownArgumentNames.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { ASTVisitor } from '../../language/visitor';
 import suggestionList from '../../jsutils/suggestionList';

src/validation/rules/KnownDirectives.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import find from '../../jsutils/find';
 import { Kind } from '../../language/kinds';

src/validation/rules/KnownFragmentNames.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { ASTVisitor } from '../../language/visitor';
 

src/validation/rules/KnownTypeNames.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import suggestionList from '../../jsutils/suggestionList';
 import quotedOrList from '../../jsutils/quotedOrList';

src/validation/rules/LoneAnonymousOperation.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import { Kind } from '../../language/kinds';
 import type { ASTVisitor } from '../../language/visitor';

src/validation/rules/NoFragmentCycles.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { FragmentDefinitionNode } from '../../language/ast';
 import type { ASTVisitor } from '../../language/visitor';

src/validation/rules/NoUndefinedVariables.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { ASTVisitor } from '../../language/visitor';
 

src/validation/rules/NoUnusedFragments.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { ASTVisitor } from '../../language/visitor';
 

src/validation/rules/NoUnusedVariables.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { ASTVisitor } from '../../language/visitor';
 

src/validation/rules/OverlappingFieldsCanBeMerged.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import find from '../../jsutils/find';
 import type { ObjMap } from '../../jsutils/ObjMap';

src/validation/rules/PossibleFragmentSpreads.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { ASTVisitor } from '../../language/visitor';
 import { doTypesOverlap } from '../../utilities/typeComparators';

src/validation/rules/ProvidedNonNullArguments.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import keyMap from '../../jsutils/keyMap';
 import { isNonNullType } from '../../type/definition';

src/validation/rules/ScalarLeafs.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { FieldNode } from '../../language/ast';
 import { getNamedType, isLeafType } from '../../type/definition';

src/validation/rules/SingleFieldSubscriptions.js

@@ -7,7 +7,7 @@
  * @flow strict
  */
 
-import type { ValidationContext } from '../index';
+import type ValidationContext from '../ValidationContext';
 import { GraphQLError } from '../../error';
 import type { OperationDefinitionNode } from '../../language/ast';
 import type { ASTVisitor } from '../../language/visitor';